1. Field of the Invention
This invention relates generally to the introduction of fuel into internal combustion engines and relates specifically to a fuel injector by means of which gasoline under high pressure is injected into a diesel type engine.
2. Description of the Prior Art
In the past a mixture of combustible fuel and air has been pumped from a carburetor to the individual cylinders of an internal combustion engine. However, the carburetor system has not been efficient since the cylinders nearest to the carburetor normally received a rich mixture, while the cylinders remote from the carburetor received a lean mixture so that the work performed by the various cylinders was not equal. Many efforts have been made to equalize the distribution of the fuel, including providing multi-barrel carburetors as well as providing fuel injectors by means of which a fixed quantity of combustible mixture was injected into each cylinder.
In most fuel injectors, gasoline under pressure is pumped into a fuel chamber having a diaphragm with a needle valve on one side and a compression spring on the other side to urge the needle valve to closed position. When the pressure of the combustible mixture overcame the pressure applied by the spring, the diaphragm and needle valve were opened to permit the mixture to be sprayed through a plurality of orifices into the combustion chamber. However, the axial movement of the needle valve must be guided and since gasoline has little or no lubricating qualities, the movement of the needle caused wear between the contacting surfaces so that the injector nozzle failed to function properly. Some examples of the prior art are the U.S. Pat. Nos. to Hesselman 1,786,844; Wiegand et al 2,430,264; Palumbo 2,470,717; Guertler 3,425,635; and Guegan et al 3,688,986.